| Figure 4. January % of total annual incidence, Pima County 1948-1998. Composites (averages) of deviation from mean Palmer Drought Severity Index (PDSI; a measure of drought conditions, where low values indicate dry conditions and high values indicate wet conditions) for Januaries with high (red) and low (blue) valley fever incidence for Pima County, Arizona. Note that a combination of wet conditions 16-24 months prior to the current January and dry conditions in the several months leading up to the current January is conducive to high valley fever incidence (and vice versa for low valley fever incidence in January). |
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